1. Technical Field
The present disclosure relates to robotics, and particularly, to a joint structure for use in an industrial robot.
2. Description of Related Art
Industrial robots are widely used in various applications to greatly reduce the burden on factory workers. A robot arm is an important part of an industrial robot. A commonly used industrial robot generally includes a plurality of individually connected robot arms, with every two robot arms connected. A common joint structure is mounted to a distal end of the robot arm to interconnect the robot arm with a clamp for gripping an object. Thus, the clamp is controlled by the robot arm to manipulate a workpiece.
The typical joint structure includes a connecting shaft and a sleeve sleeved thereon. The connecting shaft includes a substantially cylindrical first connecting portion and a substantially cylindrical second connecting portion coaxially connected with the first connecting portion. The radial dimension of the first connecting portion exceeds that of the second connecting portion, but is less than the inner diameter of the sleeve. As the sleeve is attached to the connecting shaft, a spring is received within the radial clearance formed between the connecting shaft and the sleeve, to lessen or absorb the shock of impact and prevent damage to the entire joint structure. However, in use, the sleeve is easily rotated relative to the connecting shaft because of inexact structure and precision of assembly.
Therefore, there is a room for improvement in the art.